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"Submit a URL to generate a node map of all of the requests on the page. Rapidly identify what third-parties are on your site, where your transmitted bytes are coming from and how slow your domains are !"

morale qu'on connaît déjà car on ne peut agir que - sur les cookies (enfin l'absence de) - sur le ETag (le virer pour le remplacer par du cache agressif) - éventuellement trafiquer Apache ou une machine devant Apache pour supprimer quelques headers serveurs inutiles

"combining can sometimes make loads slower, due to deferral of JS execution (have to download entire combined JS file before any of the JS can be executed). A second reason is that combining can make the resources take longer to download, due to the way that TCP slow start works"

"I did some research about how images are downloaded when media queries are involved. I wrote up some automated tests where Javascript could determine whether or not the image was requested. I've got enough data now to be able to go into detailed findings."

The advantage with WebSockets (over AJAX) is basically that there's less HTTP overhead. Once the connection has been established, all future message passing is over a socket rather than new HTTP request/response calls. So, you'd assume that WebSockets can send and receive much more messages per unit time.

SPDY is awesome. It's the first real upgrade to HTTP in 10+ years, it tackles high latency mobile networks performance issues and it makes the web more secure. SPDY is different than HTTP in many ways, but its primary value comes from being able to multiplex many requests/responses from client to server over a single (or few) TCP connections.

When we look back over the history of web performance we see a heavy focus on reducing the number of requests and getting files to the browser quickly. Our platform has changed a lot, and while optimizing for network performance remains a crucial part of our jobs, we now have to broaden our performance horizons. Our users also expect smooth scrolling, animations and interactions, even on mobile devices. In short we need to deal with not just how quickly our sites and apps load, but also how quickly they run. [video] In this session Paul takes a lightning tour of how Chrome converts the DOM into pixels, see how our code affects its workload, and arrive at a modern workflow for finding (and eliminating) rendering bottlenecks.

we can tell the browser which sockets we will need ahead of initiating the actual requests via the new preconnect hint shipping in Firefox 39 and Chrome 46